Cotton, silk and more recently braided and monofilament nylon have long been popular materials for fishing line. In recent years, wire line has gained increasing popularity for deep water trolling, providing the weight needed for carrying lures or bait down to deep fishing depths.
Wire line has increased fishermen's interest in deep trolling, and the most popular lines are nylon-covered lead-core line, braided Monel and solid, soft-drawn Monel, according to Frank T. Moss, Successful Striped Bass Fishing, p. 59 (1974 ed. Int'l Marine Pub. Co.).
Wire line provides the advantage of extra weight, sinking the line without heavy sinkers, and it offers the strength and toughness needed to fight and land big game fish. However, the stiffness of wire line makes it unsuitable for spinning reels, requiring a conventional revolving spool reel, a bait casting or game fish reel, to retrieve and handle the line. In addition, the wire line must be maintained under tension at all times to avoid snarling and tangling on the reel, requiring continuous "thumbing" pressure of the angler's thumb on the line entering the reel.
The hard unyielding metal surface of bare wire line running past the user's thumb produces friction heat, and burns may result unless a glove is worn. The bare wire's metal surface also abrades and destroys the ring-shaped or roller guides of fishing rods, whether they are surfaced with stainless steel, Carboloy or ceramic surfaces.
Another disadvantage of wire trolling line is the bright metal surface, exhibiting flashing, silver-colored reflections and distracting or frightening the fish. Many fishermen believe that trolling line colored blue or aquamarine will blend unnoticeably with the water at shoal depths, and black line is recommended for deeper trolling, where sunlight hardly penetrates.
The advent of synthetic resins and polymers has affected the fishing tackle market not only through the introduction of braided and monofilament nylon and dacron line, but also nylon-covered lead-core line and polymer covered wire leaders. A celluloid-sheathed twisted wire "snell" or leader is illustrated in Willoughby's U.S. Pat. No. 396,130, issued in 1889, and nylon-sheathed twisted and braided leaders of multi-strand stainless steel wire are illustrated in Christensen's U.S. Pat. No. 3,451,305, issued in 1969.
While a nylon coating on the surface of a wire line theoretically should improve line-handling characteristics while protecting the wire from corrosion in sea water, I have observed that such a nylon coating on wire immersed as little as 22 hours shows notable "crazing" or easily strips off when abraded or scraped, apparently lacking bonded adhesion to the metal surface. Nylon is known to absorb from three to ten percent of its weight of water (Moss, Op. cit., p. 27) apparently in minute, microscopic pores or interstices. Salt water penetrating through such microporosity and reaching the underlying surface of the metal wire can be expected to promote corrosion of the metal, and the resulting increased volume of metal oxide may actually stretch and tear the nylon coating away from the metal surface, rupturing any bond achieved between metal and nylon.
Accordingly a principal object of the present invention is to provide long lasting wire fishing line having a permanent tough protective corrosion-proof coating.
Another object of the invention is to provide such wire fishing line having smooth "level-winding" coiling properties, avoiding snarling and tangling when being re-wound on the spool of the reel.
A further object of the invention is to provide such wire fishing line having a smooth resilient surface of high lubricity and low coefficient of friction, reducing friction and heat on the angler's thumb and on fishing rod rollers and guides during use.
Other objects of the invention will in part be obvious and will in part appear hereinafter.